Ammunition



Dec. 19, 1933. w. H. WOODFORD AMMUNI TION Filed Jan. 28, 1933 INVENTOR.WATSQN H .Wooo FORD ATTORNEY Patented Dec. 19, 1933 UNITED STATES PATENTOFFICE ANIMIUNITION Application January 28, 1933. Serial No. 653,957

12 Claims.

This invention relates to ammunition and particularly to theconstruction of the bodies of paper shot shells and tubes for themanufacture of such shot 'shell .bodies.

Shot shells, as ordinarily constructed, comprise a body which isessentially a paper cylinder, having fitted thereto a head of brass orother suitable metal, which head comprises a cylindrical flange adaptedto receive and fit closely about an end section of the paper body. Abase wad is fitted inside the end of the paper body which is encircledby the flange of the metal head, and serves among other things to effectsuch a contact of the paper body and the metallic head as will preventthe escape of powder gas in the firing of the shell.

Since in firing a very high pressure is produced within the body of theshot shell, such paper bodies are prone to a variety of failures, a substantial fraction of which occur near the top of the metal flange.Various devices have been proposed for strengthening shell bodies,particularly at this vulnerable point, as well as for securing a moreperfect gas seal between the shell body and the metal of the head.

It is an object of this invention to materially increase the mechanicalstrength of paper shell bodies by subjecting them tocertainmanufacturing operations hereinafter more fully described.

A further object of the invention is to substantially eliminate shellbody defects by rendering the shell body and particularly the outersurface thereof somewhat elastic and less liable 5 to failure understress.

More specifically, the invention contemplates a shell body of greatlyimproved resistance to rupture under stress and of improved appearance,these results being secured by forming in the shell body or the tubesfrom which shell bodies are made of a series of alternate depressionsand ridges.

In the drawing, Fig. 1 is a side elevation of a shot shell including oneembodiment of the invention.

Fig. 2 is a fragmentary enlarged transverse section of a portion of ashell body such as is illustrated in Fig. 1.

Fig. 3 is a similar fragmentary transverse section, showing a slightlydifferent form of ridging or corrugation.

Fig. 4 is a fragmentary perspective of a shell tube showing a slightlydifferent arrangement of the ridges or corrugations. i5 The shot shellillustrated in Fig. 1 comprises the usual metallic head 10 having acylindrical flange 11, which flange encircles the end section of a paperbody 12. Such paper bodies are, prior to assembly with the metallichead, cut from tubes of a length of several shell bodies, which tubesare rolled from sheets of specially prepared paper. The wall of the tubecomprises 4 or 5 layers of paper, secured together by a suitableadhesive such as starch. The tubes may also be treated either prior orsubsequent to cutting with suitable heat absorbent and moisture proofingmaterials.

Prior to the present invention it has been universal practice to leaveboth the inside and outside walls of the tubes in a smooth condition,j'ust if as they are rolled from the paper or delivered from a sizingand burnishing die. The present invention comprises the discovery thatby forming in one surface of the tube a series of grooves separated bycomparatively narrow undepressed lines a very substantial increase inmechanical strength is secured. The proportions of the depressed andundepressed lines are such that the entire surface presents a corrugatedor ribbed appearance. A shell body made from a tube thus corrugated isshown in Fig. 1, the undepressed lines or ridges being identified by thenumeral 13 and they grooves between the ridges by the numeral 14. Suchgrooves and ridges may take a variety of shapes, thus Fig. 2 shows anenlarged section of -a tube in which they are of angular configurationwith substantially flat bases and tops; while Fig. 3 shows a modified Vconstruction with curving bases and tops.

The corrugations may run in any desired direction with respect to theaxis of the tube, thus in Fig. 1 they are illustrated as extendingparallel to the axis of the tube, while Fig. 4 shows a construction inwhich the corrugations form a spiral about the tube. The pitch orspacing of adjacent depressed lines may be greatly varied, the typicalor average arrangement comprising about 20 or 25 such lines to the inch,and they are preferably applied to the exterior surface. Their depth maybe a comparatively small fraction of the 100 thickness of the tubestock.

The corrugation of the surface of the tube may be effected in a varietyof ways, a preferred method being to draw a smooth tube through a dieprovided with properly spaced and shapedprojec- 105 tions for formingthe desired number and shape of grooves. If the corrugations are toextend axially of the tube and shell body as shown in Fig. I the tubesare, during this operation, held against rotation. If a spiralcorrugation, such as 110 shown in Fig. 4, is desired, the tubes arerotated while passing through the die at arate depending upon thedesired pitch of spiral.

A very remarkable increase in the mechanical strength of tubes issecured by thus corrugating one of their surfaces. Ordinary smoothbodied shot shells are never entirely free from firing defects. Firingof freshly prepared shells under ordinary conditions results in a numberof casualties of the general order of 1%, whereas an extensive test ofcorrugated body shells resulted in casualties of one-tenth of 1%, all ofwhich were slight and unimportant. A severe test to which shot shellsare ordinarily subjected consists in first drying them in a vacuum forabout 24 hours and then exposing them for several hours to a temperatureof about l0 F. This test of ordinary tubes results in about 40%casualties, many of which are serious; whereas the casualties for thecorrugated tubes of this invention are less than 5% and are all of aminor nature. The roughened surface likewise facilitates handling of theshells as well as enhancing their appearance. A very substantial advancein the art of shot shell manufacture has thus been made.

Since the method of strengthening shot shell bodies by corrugating theirsurface is broadly new, the appended claims are to be broadly construed.

What is claimed is:

1.- The method of strengthening the paper bodies of shot shells whichcomprises the rolling of a sheet of paper into a smooth surfaced tube,and the forming of one surface of such tube into a series of alternategrooves and ridges.

2. The method of strengthening the paper bodies of shot shells whichcomprises the rolling of a sheet of paper into a smooth surfaced tube,and the forming of one surface of such tube into a series of alternategrooves and ridges. by passing such tube through a suitable die.

3. The method of strengthening the paper bodies of shot shells whichcomprises the rolling .of a sheet of paper into a smooth surfaced tube,and the forming of one surface of such tube into a series oflongitudinally extending .alternate grooves and ridges.

4. The -,method of strengthening the paper bodies of shot shells whichcomprises the rolling of a sheet of paper into a smooth surfaced tube,and the forming of one surface of such tube into a series of spirallydisposed alternate grooves and ridges.

5. The method of strengthening the paper bodies of shot shells whichcomprises the rolling of a sheet of paper into a smooth surfaced tube,and the forming of one surface of such tube into a series of spirallydisposed alternate grooves and ridges by passing said tube through a dieduring relative rotation of said tube and die.

6. In the manufacture of tubes for shot shell bodies, the method whichcomprises rolling a tube from a plain sheet, and subsequently passingsaid tube through a die to form in one surface of said tube a pluralityof relatively small evenly spaced indentations.

7. A non-metallic shot shell body of substantial wall thickness havingimpressed in its exterior surface a series of regularly spacedrelatively small longitudinally extending indentations which strengthenthe body and facilitate handling.

8. In the manufacture of tubes for shot shell bodies, the method whichcomprises rolling a tube from a plain sheet, and subsequently forming inone surface of said tube a plurality of relatively small evenlyspacedindentations.

9. In the manufacture of shot shell tubes the method which comprisesforming in the tube.

body alternating lines or areas of compressed and uncompressed stock.

10. A shot shell comprising a base and a nonmetallic body, said bodycomprising alternating lines of compressed and uncompressed stock.

11. A shot shell having a base and a nonmetallic body, said body havinga plurality of parallel longitudinally extending grooves impressed onthe surface thereof, said grooves strengthening the body andfacilitating handling.

12. A non-metallic shot shell body comprising a wall of substantialthickness having impressed in its exterior surface a plurality ofrelatively shallow lines or grooves which strengthen the body andfacilitate handling.

WATSON H. WOODFORD.

